1. Field of the Invention
The present invention relates to a figure management system and a figure modifying method using the same. More particularly, the invention pertains to a method of making cross reference among a plurality of related figures and enabling efficient utilization of common objects repetitively appearing on the plural related figures, attributes of the common objects, network connections, etc. in a multiple-figure management system or a facility management system based on use thereof, such as a geographic information system (GIS) or a computer-aided design system (CAD), and further the invention is concerned with a figure management system for modifying a plurality of related figures while maintaining mutual consistency through detection of any possible discrepancy among the plural related figures and a figure modifying method using the same.
2. Description of the Related Art
Recent years have seen the increasing prevalence of geographic information systems (GIS) developed for providing electronic forms of paper-medium maps. In the GIS, geographic map figures are stored and processed in a computer thereof for managing names and attributes of various objects indicated by graphic features on figures, road connection networks, and other relational data of graphic features.
The GIS allows a user to make a search for a map of a desired geographic region and to look up detailed attribute data of an object represented by a corresponding on-map feature through selection thereof. Having various functions and means for managing, retrieving and processing geographic map figures and object attribute data, the GIS is capable of supporting facility management activities or urban planning activities for a local government, for example. International standardization concerning various functions of GIS is currently under way at the ISO/TC211 and Open GIS Consortium.
Referring to FIG. 16, there is shown a representative model of a conventional GIS used for figure management. In this system, geographic map figures are stored and managed in a figure database (DB) thereof, and attribute data of objects represented by graphic features on figures are stored and managed in an attribute DB thereof. Attributes of each object include such inherent data thereof as a name, a category, a superintendent, a date of construction (year, month, day), etc. For association between graphic features and object attributes, an ID code is assigned to each graphic feature, and attribute data corresponding to each assigned ID code is stored into the attribute DB. Thus, in this system, a user can make reference to attribute data by selecting a corresponding graphic feature on a figure.
Referring to FIG. 17, there is shown a configuration of a conventional GIS based on the Simple Feature Specifications proposed by the Open GIS Consortium. In this system, geographic map figures themselves are not subjected to management. Objects are handled using an attribute DB only. In addition to such attribute data of objects as categories (e.g., houses, roads, crossroads), names, superintendents, dates of construction (year, month, day), etc., graphic feature data thereof are managed through the use of the attribute DB. When it becomes necessary to prepare new figures, they can be generated using a set of graphic feature data.
In conventional GIS""s, object attributes and on-figure graphic features are associated in a one-to-one correspondence. In actuality, however, maps and figures are prepared by partially mapping actual object relationships according to rules predetermined to meet a particular purpose of application, and plural kinds of figures such as {fraction (1/500)}-scale maps, {fraction (1/2500)}-scale maps, and topological figures may be used. For carrying out facility management activities, it is required to handle various kinds of figures concerning a single part to be managed. In the conventional GIS""s, integrated management is not allowed concerning relationships between plural figures and actual objects.
More specifically, in preparation of a map meeting a particular purpose of application, it may be required to use figures having different scales, such as {fraction (1/500)}-scale maps showing detailed geographic information and {fraction (1/2500)}-scale maps showing overall geographic information. Further, the use of plural kinds of projection figures such as Mercator projection figures and Lambert projection figures may be required in some cases.
Still further, network topological figures in which object positions are rearranged for easy understanding of object connection relationships, such as electric-car line route diagrams and electric circuit diagrams, may be used. These network topological figures are prepared in a variety of forms according to presentation ranges, object representations, kinds of omitted objects, and other conditions concerning viewpoints of respective system users. A sketch map for location or road guide may also be regarded as a kind of topological figure.
Further, even among figures of the same kind, there are a multiplicity of variations, including modified figures, unmodified figures, figures prepared by different cartographers, figures prepared using different facility management systems, etc.
In operation of the conventional GIS""s, a particular problem exists in that the cost of maintenance for modifying or updating figures is rather high. That is to say, at the time of maintenance of figures, a human operator searches the GIS for relevant figures and modifies them as required. Since the figures are modified by each human operator, errors or omissions may occur in modification to impair consistency among figures, resulting in a substantial increase in the cost of figure maintenance.
It is therefore an object of the present invention to provide a figure modifying method for use in a figure management system in which plural kinds of figures and attribute data are processed for the same part to be managed, the figure management method being so arranged as to reduce the cost of maintenance of figure management and to eliminate possible discrepancy among a plurality of figures including topological figures and possible discrepancy between figures and object attributes for maintaining overall system consistency at the time of figure modification.
In accomplishing this object of the present invention and according to one aspect thereof, there is provided a figure modifying method for use in a figure management system which has a figure DB for storing data of plural kinds of figures including topological figures concerning the same part to be managed, an attribute DB for storing attribute data of objects represented by graphic features on the figures, input and output devices for inputting and outputting figure data and attribute data, and a signal processing apparatus for managing figure data and attribute data through use of the figure DB, the attribute DB and the input and output devices, the figure modifying method being arranged for entering new figure data and for modifying a part of existent figure data stored in the figure DB, wherein, at the time of modification of any figure data, an absolute position of each object represented by an on-figure graphic feature and at least one of connection-association relationships thereof with other objects are compared with existent object attribute data indicating object absolute positions and connection-association relationships with other objects which are contained in the attribute DB, wherein an ID code common to the existent object attribute data contained in the attribute DB is assigned to each matched graphic feature for establishing a relationship, and wherein any graphic feature not matched with the existent object attribute data stored in the attribute DB is output onto an output device of the figure management system ask discrepant point or as a point to be renewed, and then correction is performed on the discrepant point or the point to be renewed through manual operation or by a feature-attribute automatic matching function of the signal processing apparatus of the figure management system.
Further, according to another aspect of the present invention, when any graphic feature is judged to be a discrepant point or a point to be renewed, a corresponding object attribute is modified by an attribute automatic modifying function included in the signal processing apparatus of the figure management system. To be more specific, a newly added object is registered, an attribute of a deleted object and an attribute of an object whose connection relationship or position has been changed are modified, and an attribute of an object in relation thereto is modified according to the attribute modification thus made.
In the above processing, plural kinds of figures including topological figures are applicable. Addition of a new figure and partial correction of an existent figure are also allowed in modification.
Still further, according to another aspect of the present invention, there is provided a figure management system in which the above-mentioned figure modifying method is to be implemented. The figure management system comprises a first processing section and a second processing section. In an arrangement wherein the figure DB for storing plural kinds of figure data concerning the same part to managed, the attribute DB for storing attribute data of objects represented by graphic features on figures, and the input and output devices for inputting and outputting the figure data and attribute data are interconnected, the first processing section is used to carry out correction on a discrepant point or a point to be renewed through manual operation or by the feature-attribute automatic matching function of the signal processing apparatus, and the second processing section is used to implement the attribute automatic modifying function thereof.
In a preferred embodiment of the present invention, the signal processing apparatus is embodied as a computer, and the first and second processing sections are realized by using information storage media containing application programs for executing respective functions.
According to the present invention, even in a situation where topological figures and different kinds of maps, e.g., maps based on different scales, maps based on different projection-methods, etc. are used mixedly, the following advantages are provided:
(1) At the time of figure modification, in case that entire replacement is made with external figures having no ID codes, an ID code can be assigned to each feature on figures efficiently using a proper combination of manual operation and the feature-attribute automatic matching function of the signal processing apparatus.
(2) When any feature on a figure sheet is edited and modified, a corresponding feature on a related figure is referenced and recorded as a candidate feature for automatic modification on the computer.
(3) When a plurality of related figures are given, any possible discrepancy in positions or connection relationships of objects indicated by features on respective figures can be found and corrected with ease.
These and other objects, features and advantages of the present invention will become more apparent in view of the following detailed description of the preferred embodiments in conjunction with accompanying drawings.